Thrombocytopenia-7 (THC7) is an autosomal dominant disorder characterized by reduced peripheral platelet count. The expression and severity of the disorder is highly variable: some patients have no bleeding symptoms, whereas other have recurrent petechiae, epistaxis, or more severe bleeding episodes. A common finding is decreased alpha-granules in the platelets. There are variable findings on light and electron microscopic analysis: some patients have normal platelet morphology, whereas others show abnormal platelet morphology with cytoskeletal defects. Flow cytometric studies may show reduced expression of platelet membrane glycoproteins and activation markers (summary by Lentaigne et al., 2019 and Leinoe et al., 2021).
For a general phenotypic description and a discussion of genetic heterogeneity of thrombocytopenia, see 313900. [from
OMIM]